GS START - Medicines commonly Prescribed in General Surgery

Medicines commonly prescribed in general surgery - quiz

OBJECTIVEs

•Know the renal dose adjustments on common anti-infectives prescribed by GSD

•Be familiar with the precautions of commonly prescribed medications and hence select appropriate choices within each class

•Able to transcribe medications accurately

•Reduce near misses and medication errors

•Promote safe and accurate prescribing practice

Case Review 1

Multiple Choice

1. Which antibiotic require renal dose adjustment?

• Ceftriaxone

• Clindamycin

• Amoxicillin/ Clavulanic acid (Co-amoxiclav)

• Metronidazole

Multiple Choice

2. Which of the following is true about beta-lactams?

• ALL beta-lactams should be dose-reduced in the setting of renal impairment

• Amoxicillin/Clavulanic acid (Augmentin) should be given as ON dosing in ESRF patients on hemodialysis because the drug is moderately dialyzable

• Out of the carbapenems, ONLY meropenem interacts with sodium valproate and reduces serum drug concentration of the latter

• Piperacillin-tazobactam is preferred over carbapanems for treatment of extended spectrum beta-lactamases (ESBL) producing bacteri

Multiple Choice

3. Which of the following is true with regard to tramadol?

• It can reduce seizure threshold; generally avoid use in patients with history of seizure

• It is contraindicated in patients with cirrhosis

• The maximum dose of tramadol in patients on dialysis is 100mg/day

• The maximum dose of tramadol in patients with cirrhosis is 300mg/day

Multiple Choice

4. What is the minimum time interval between the 1st dose of palonosetron and ondansetron?

• 24 Hours

• 48 Hours

• 72 Hours

• 8 Hours

Multiple Choice

5. NSAIDs should generally be avoided in the following condition, EXCEPT

• History of GI bleed

• 75 years old and above

• Acute kidney impairment

• Myocardia Infarction and taking Aspirin

Multiple Choice

6. Which of the NSAIDs is preferred in a patients with cardiovascular disease who absolutely need an NSAID?

• Diclofenac

• Celecoxib

• Naproxen

• Etoricoxib

Multiple Choice

7. Which of the following statement is true

• One bottle of oral fleet (Fleet phospho-soda) should be given to a patient on dialysis who has severe constipation and refused suppository and enema

• Forlax (polyethylene glycol 4000) may be given to a patient on dialysis for severe constipation

• Oral fleet 5ml BD is contraindicated for a patient on dialysis with hypophosphatemia (PO43- : 0.6)

• Polyethylene glycol containing laxatives works by stimulating enteric nerves to cause colonic contractions

Case Review 2

Multiple Choice

8. Correct EPIC order for Betanicardia (Atenolol 50mg/ Nifedipine SR 20mg ) 1 Cap OM:

• Atenolol 50mg OM + Nifedipine LA 30mg OM

• Atenolol 50mg OM + Nifedipine Retard 20mg OM

• Atenolol 50mg OM + Nifedipine Cap 20mg OM

• Atenolol 50mg OM + Nifedipine LA 60mg OM 

Multiple Choice

9. Correct EPIC order for:

Multiple Choice

10. Correct EPIC order based on medication reconciliation:

Multiple Choice

11. Correct EPIC order based on NEHR:

Case Review 3

A 69 year old female has a history of HTN, HLD, IHD, T2DM, asthma, rheumatoid arthritis, fatty liver, chronic gastritis, glaucoma, osteoporosis. Allergic to amoxcillin (pruritus)

Latest weight: 70kg,  adjusted body weight: 53.14kg, baseline sCr: 89umol/L, Crcl 44ml/min, eGFR 54.5mL/min/1.73 m². Baseline Hb 12x1012/L

Patient was admitted to the ED with 24hours history of severe abdominal pain radiating to the back, nausea and bilious emesis.

Objective parameters in ED: Tmax 37.2°C, HR 110bpm, RR 18/min, SBP/DBP 100/60. Random hypocount: 16mmol/L.

​

Multiple Choice

13. The diagnosis was acute pancreatitis likely secondary to gallstones. Which of the medication(s) should preferably be withheld on admission?

• Frusemide, potassium chloride SR tab, aspirin, bisoprolol, alendronate, glipizide, lovastatin, metformin, methotrexate, folic acid

• Aspirin, bisoprolol, alendronate, glipizide, lovastatin, metformin, methotrexate, folic acid

• Frusemide, potassium chloride SR tab, aspirin, bisoprolol, alendronate, methotrexate, folic acid

• Withhold all old medications

Answer

Answer: Frusemide, potassium chloride SR tab, aspirin, bisoprolol, alendronate, glipizide, lovastatin, metformin, methotrexate, folic acid

•Due to hypotension from volume depletion 2” to 3rd spacing in pancreatitis causing AKI, frusemide should be withheld.

•Potassium choride should be withheld because of mildly elevated K.

•Aspirin may or may not be withheld if the patient is planning for ERCP.

•Bisoprolol should be withheld to avoid further hypotension and worsening of AKI and restarted when patient is more stable with rising BP.

•Alendronate should be withheld because it is not essential to be restarted now and Crcl is <35ml/min.

•More prudent to withhold glipizide until oral intake is established; metformin should be withheld because of AKI (increases risk of worsening lactic acidosis since it is cleared renally) with high lactate.

•Methotrexate and folic acid should be withheld because the former can cause worsening of liver function (it is also metabolized hepatically) and should generally not be restarted in septic patients to prevent suppression of immune system

Multiple Choice

The decision was to start empiric antibiotics for acute pancreatitis with raised TW PCT, CRP. Which of the following shows the appropriate choice and dose of antibiotic(s)?

14. PMH: HTN, HLD, IHD, T2DM, asthma, rheumatoid arthritis, fatty liver, chronic gastritis, glaucoma, osteoporosis. Allergic to amoxcillin (pruritus)

• IV Augmentin 1.2g q12H

• IV ciprofloxacin 400mg q12H + IV metronidazole 500mg q12H

• IV ceftriaxone 2g q12H + IV metronidazole 500mg q12H

• IV ciprofloxacin 400mg q24H + IV metronidazole 500mg q12H

​Answer

Answer: IV ciprofloxacin 400mg q24H + IV metronidazole 500mg q12H.

Augmentin should not be used because the patient is allergic to amoxicillin. Ceftriaxone may be considered if there is no safer choice. Previous literature cited that cross-reactivity between penicillins and cephalsporins occurs at ~8% although the true incidence is currently said to be 2%. However, the dose should be 2g q24H for non-CNS related infections. IV Ciprofloxacin might thus be a safer choice, but it should be renally dose adjusted to 400mg q24H for Crcl <30ml/min.

Multiple Choice

15. Resonium was initiated for treatment of hyperkalemia. Which of the following order on eIMR is encouraged?

• PO Resonium 15g/60mL TDS

• PR Resonium 30g/120mL ONCE DOSE

• PO Resonium 15g/60mL TDS x 3 days

• PR Resonium 30g/120mL OM x 7 days

Answer

Answer: PR Resonium 30g/120mL ONCE DOSE

K of 5mmol/L is not overtly high, hence reduction of K should not be too aggressive especially with ongoing fluid resuscitation, satisfactory urinary output.

Multiple Choice

16. Glipizide and metformin was withheld and referral was made to the integrated diabetes care program (IDCP). Insulin was initiated with SCSI Actrapid while patient was kept NBM with dextrose containing drip.Which of the following shows the appropriate order (excluding dose) of insulin?

• SC Insulatard 1000units/10ml Inj + CBG monitoring TDS (with meals) + BEDTIME and SCSI Actrapid TDS (with meals, omit if NBM)

• SC Insulatard 1000units/10ml Inj+ CBG monitoring q6H and SCSI Actrapid q6H

• SC Insulatard 300units/3ml Inj PENFILL+ CBG monitoring q6H and SCSI Actrapid q6H

• SC Insulatard 300units/3ml Inj PENFILL + CBG monitoring TDS (with meals) + BEDTIME and SCSI Actrapid TDS (with meals, omit if NBM)

Answer

Answer: SC Insulatard 1000units/10ml Inj+ CBG monitoring q6H with SCSI Actrapid q6H

CBG monitoring should be done q6H with SCSI Actrapid dosed at q6H for patients kept NBM. Basal insulin is recommended if CBG is persistently above 12mmol/L.

Case Review 4

A 65 year old man has PMH of HTN, HLD, type 2 diabetes mellitus (DM) and CKD stage 2. Other relevant history: ex-social drinker, (stopped drinking since discharged on 18/1/2017 for mild acute pancreatitis), non-smoker.

During regular polyclinic follow-up on 2/12/18, linagliptin was added (HbA1c 7.8%).

Medications on admission:

1. Hydrochlorthiazide 25mg OM

2. Amlodipine 7.5mg OM

3. Irbesartan 150mg OM

4. Rosuvastatin 10mg OM

5. Metformin 1g BD

6. Glipizide 10mg BD

7. Linagliptin 5mg OM

Latest weight: 48kg, baseline sCr: 100umol/L, Crcl 44ml/min, eGFR 69.1 mL/min/1.73 m²

​On 29/12/18, the patient presented to ED with severe epigastric pain and nausea x 2 days.

Objective parameters in ED: Tmax 37.8°C, HR 110bpm, RR 20/min, SBP/DBP persistently ~180/100mmHg. Random hypocount: 14mmol/L

​

Multiple Choice

17. Two sets of blood culture was taken after which IV gentamicin once dose and IV Augmentin was ordered. Which of the following shows the correct doses for the 2 antibiotics?

• IV gentamicin 240mg ONCE (5mg/kg) + IV Augmentin 1.2g q8H

• IV gentamicin 140mg ONCE (3mg/kg) + IV Augmentin 1.2g q12H

• IV gentamicin 240mg ONCE (5mg/kg) + IV Augmentin 1.2g q12H

• IV gentamicin 140mg ONCE (3mg/kg) + IV Augmentin 1.2g q8H

IV gentamicin 240mg ONCE (5mg/kg) + IV Augmentin 1.2g q12H

Although Crcl in ED was 27ml/min, there is no need for renal dose adjustment when giving once dose of gentamicin because of it’s concentration dependent kill and post antibiotic effect. Renal dose adjustment for IV Augmentin is however needed.

Multiple Choice

18. Which of the following anti-hypertensive(s) is/are inappropriate to continue and why?

• Hydrochlorothiazide because it will worsen hyperglycemia

• Discontinue all and start atenolol 75mg OM due to high BP and HR

• All are appropriate to continue

• Hydrochlorothiazide and Irbesartan as Crcl <30ml/min

Hydrochlorothiazide and Irbesartan as Crcl <30ml/min

Hydrochlorothiazide ineffective at Crcl< 30ml/min. Irbesartan should also be withheld because of AoCKD.

Multiple Choice

19. In view of pain score 8/10, analgesia was started. Which of the following is the most appropriate combination for the patient?

• IV paracetamol 1g q6H + PO etoricoxib 90mg OM + IV tramadol 50mg q8H

• IV paracetamol 500mg q6H + IV tramadol 75mg q8H

• IV paracetamol 1g q6H + IV tramadol 50mg q8H + IM pethidine 50mg ONCE

• IV paracetamol 500mg q6H + IV tramadol 50mg q8H

IV paracetamol 500mg q6H + IV tramadol 50mg q8H

• NSAIDs (etoricoxib and pethidine) should not be initiated during AoCKD/AKI because they may further worsen renalblood flow and AoCKD

• Accumulation of toxic metabolite normeperidine is associated with tremulousness, delirium and seizures

• Dose of tramadol should be reduced to not more than 200mg/day in Crcl <30ml/min

Objective parameters on 30/12/18: Tmax 38.2°C, HR 90bpm, RR 22/min, SBP/DBP ~145/90mmHg. Hypocount range: 12-16mmol/L

Subjective: Epigastric pain better (pain score 4/10).

IV Augmentin was continued while awaiting blood culture results. The patient was allowed diet.

Multiple Choice

20. Which of the following anti-hyperglycemic agent (s) is/are the most appropriate to initiate now?

• Metformin + glipizide

• Metformin + glipizide + linagliptin

• Glipizide + linagliptin

• SC basal Insulin + SCSI

SC basal Insulin + SCSI

• Not recommended to restart metformin as concurrent sepsis and AoCKD increase risk of lactic acidosis

• Glipizide might not be an appropriate agent to restart due to reduced appetite

• Linagliptin should also not be due to history of pancreatitis

• Given that random blood glucose levels were above 10mmol/L, SC basal insulin was appropriate to be initiated with SCSI

One week later, the patient was able to be discharged. His renal function has returned to baseline, sCr 99umol/L (Crcl 45ml/min), liver enzymes were normalized, epigastric improved.

      Medications on discharge:

1. Hydrochlorthiazide 25mg OM

2. Amlodipine 7.5mg OM

3. Irbesartan 150mg OM

4. Rosuvastatin 10mg OM

5. Metformin 1g BD

6. Glipizide 10mg BD

Multiple Choice

21. The doctor wished to prescribe a short course of analgesia. Which of the following analgesia combination is the most appropriate?

• PO paracetamol 1g q6h x 2 weeks + PO tramadol 50mg q8H PRN x 5 days

• PO paracetamol 500mg q6H PRN x 2 weeks + PO etoricoxib 90mg OM PRN x 5 days

• PO paracetamol 1g q6H x 2 weeks + PO etoricoxib 90mg OM PRN x 5 days

• PO paracetamol 500mg q6H PRN x 2 weeks + PO tramadol 50mg q6H x 5 days

PO paracetamol 1g q6h x 2 weeks + PO tramadol 50mg q8H PRN x 5 days

• NSAIDs should not be given to patients on ACEi/ARB and diuretics

• Combined use of ACEi/ARB with a diuretic and an NSAID, including cyclo-oxygenase-2 (COX-2) inhibitors increases risk of triple whammy

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